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| author | Bo Shen <voice.shen@atmel.com> | 2014-03-19 14:48:44 +0800 |
|---|---|---|
| committer | Andreas Bießmann <andreas.devel@googlemail.com> | 2014-05-27 00:10:40 +0200 |
| commit | 12bbc0ba813463fd3c7b433c37abcd3f67b37ff3 (patch) | |
| tree | 52e65f5a83053296b9f3e75c41f4b5f41dfc4f38 /arch/arm/cpu/at91-common | |
| parent | 49692c5f517d8e44ed9db0de778728fe7d2a300c (diff) | |
| download | blackbird-obmc-uboot-12bbc0ba813463fd3c7b433c37abcd3f67b37ff3.tar.gz blackbird-obmc-uboot-12bbc0ba813463fd3c7b433c37abcd3f67b37ff3.zip | |
ARM: atmel: switch to main crystal osc for SPL boot
If without switch to main crystal oscillator, the sama5d3 SoC will
use internal on chip RC oscillator.
In order to get better accuracy, switch to main crystal oscillator.
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Diffstat (limited to 'arch/arm/cpu/at91-common')
| -rw-r--r-- | arch/arm/cpu/at91-common/spl.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm/cpu/at91-common/spl.c b/arch/arm/cpu/at91-common/spl.c index 7f4debb912..cbb5a529da 100644 --- a/arch/arm/cpu/at91-common/spl.c +++ b/arch/arm/cpu/at91-common/spl.c @@ -20,6 +20,43 @@ static void at91_disable_wdt(void) writel(AT91_WDT_MR_WDDIS, &wdt->mr); } +static void switch_to_main_crystal_osc(void) +{ + struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC; + u32 tmp; + + tmp = readl(&pmc->mor); + tmp &= ~AT91_PMC_MOR_OSCOUNT(0xff); + tmp &= ~AT91_PMC_MOR_KEY(0xff); + tmp |= AT91_PMC_MOR_MOSCEN; + tmp |= AT91_PMC_MOR_OSCOUNT(8); + tmp |= AT91_PMC_MOR_KEY(0x37); + writel(tmp, &pmc->mor); + while (!(readl(&pmc->sr) & AT91_PMC_IXR_MOSCS)) + ; + + tmp = readl(&pmc->mor); + tmp &= ~AT91_PMC_MOR_OSCBYPASS; + tmp &= ~AT91_PMC_MOR_KEY(0xff); + tmp |= AT91_PMC_MOR_KEY(0x37); + writel(tmp, &pmc->mor); + + tmp = readl(&pmc->mor); + tmp |= AT91_PMC_MOR_MOSCSEL; + tmp &= ~AT91_PMC_MOR_KEY(0xff); + tmp |= AT91_PMC_MOR_KEY(0x37); + writel(tmp, &pmc->mor); + + while (!(readl(&pmc->sr) & AT91_PMC_IXR_MOSCSELS)) + ; + + tmp = readl(&pmc->mor); + tmp &= ~AT91_PMC_MOR_MOSCRCEN; + tmp &= ~AT91_PMC_MOR_KEY(0xff); + tmp |= AT91_PMC_MOR_KEY(0x37); + writel(tmp, &pmc->mor); +} + void at91_plla_init(u32 pllar) { struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC; @@ -76,6 +113,8 @@ u32 spl_boot_mode(void) void s_init(void) { + switch_to_main_crystal_osc(); + /* disable watchdog */ at91_disable_wdt(); |
